To estimate the total population of weaver birds in the woodland, we can use the Lincoln-Petersen index (part of mark-recapture methods). The formula is:
\[ \frac{N}{M} = \frac{C}{R} \]
Where:
- \( N \) is the estimated total population size
- \( M \) is the number of marked individuals released (435)
- \( C \) is the total number of individuals captured during the second capture (620)
- \( R \) is the number of marked individuals recaptured (75)
Rearranging the formula to solve for \( N \):
\[ N = \frac{M \times C}{R} \]
Substituting the values:
\[ N = \frac{435 \times 620}{75} \]
Now, calculating that:
- Calculate \( 435 \times 620 \):
\[ 435 \times 620 = 270300 \]
- Now divide by \( 75 \):
\[ N = \frac{270300}{75} = 3604 \]
Thus, the approximate size of the weaver bird population in the woodland is 3604.